To determine the UV-VISIBLE spectra of rod and cone visual pigments and colored oil droplets using microspectrophotometry of single receptors. To determine why cone pigments are lost to detergent extraction by examining the lability of cone pigments to various agents by MSP and comparison of extract lambda max with MSP lambda max. To determine diffusion coefficients of several visual pigments and their photoproducts in rod and cone membranes and alteration of diffusional properties caused by various treatments. To determine the sidedness of visual pigment in membranes of rods and cones by impermeable dye labelling and identification by acrylamide gel electrophoresis. To elucidate the mechanism of several kinetic phases of birefringence change of ROS initiated by bleaching through comparison with kinetics of chromophore rotation and by various treatments - glutaraldehyde, hydroxylamine, pyridine nucleotide. Microphotometric assay to be performed with a microretardometer and by dichroic MSP.